1. Field of the Invention
The present invention relates generally to apparatus for facilitating recovery of mechanical energy from fluids and more particularly to apparatus for recovering energy from low pressure gases available from industrial or natural sources.
2. Description of the Prior Art
Devices such as the water wheel are known which facilitate the conversion of potential or kinetic energy of fluids into useful work. Variations of the water wheel have been proposed which extract energy from gases. This kind of apparatus generally comprises a vaned wheel which is at least partly submerged in a body of a liquid. A supply of gas is introduced at the bottom of the wheel displacing liquid from the compartments defined by the wheel's vanes. The displacement of liquid from these lower compartments by the gas produces unbalanced buoyant forces which impart torque and consequent rotation to the wheel. (See for example, U.S. Pat. Nos. 6,995; 271,040; and 2,135,110.)
Another device which employs buoyancy forces to recover mechanical energy from a gas comprises fillable bladders serially disposed on a continuous member for movement about a vertically disposed track-like path through a liquid. The bladders are sequentially filled with gas to become buoyant near the lowermost level of their travel and, at the uppermost level of their travel, the bladders are sequentially collapsed for the return downward travel through the liquid. The cumulative buoyancy force of the gas filled bladders imparts motion to the bladder supporting member. (See, for example, U.S. Pat. No. 3,907,454.)
In the past, because of low cost energy sources, industrial plants and processes have frequently exhausted low pressure process gases without attempting to utilize the energy available from the gases. In many cases the cost of equipment which would be necessary to extract the energy has not been justified because of the low initial fuel costs. As fuel costs have risen, the desirability of using the energy of low pressure gases has increased. In addition to gases available in industrial environments, natural sources of low pressure gas flows are or can be made available in many localities. Water-wheel type devices of the sort proposed by the prior art do not, in many instances, provide practical or effective ways to extract energy from these low pressure gas sources.